Talk:Mass spectrometry

Comment on new section called 'steps'

This new section is a major step backwards because it duplicates the sections lower down on parts of a mass spectrometer and hence just causes confusion. Also it erroneously implies that particles in a source are always atomic, and that they are always ionized using an electron gun. This is just as bad as an earlier introduction that implied particles are always molecular. This section should be deleted! Radiogenic (talk) 04:46, 31 December 2013 (UTC)

I agree with Radiogenic.Neuloja (talk) 11:53, 18 January 2014 (UTC)

Agree and have removed the section. Vsmith (talk) 14:48, 18 January 2014 (UTC)

Comment on new (intro) photo of mass spectrometer

This photo is not helpful in explaining mass spectrometry because it emphasizes a non-relevant aspect, ie the user/computer/lab, at the expense of the actual instrument. It should be replaced with a photo that shows the core aspect of a mass spectrometer, which is the part that creates a spectrum of masses. — Preceding unsigned comment added by Radiogenic (talk • contribs) 05:20, 11 May 2014 (UTC)

Applications

Mass spectrometers can be used to (slowly) filter out isotopes within a substance. This has been used by researchers of quantum computing to generate pure Silicon-28, which is needed to insulate a single Phosphorus atom from the rest of the equipment; This is one of the possible solutions to the problem of actually constructing a qubit. This method of generating Silicon-28 is a very cheap alternative to the other method; Quantum computing researchers would've found getting silicon-28 to be prohibitively expensive had it not been for the Avogadro project coincidentally also needing Silicon-28. 0xFFF1 (talk) 07:31, 26 October 2016 (UTC)

References

Heavier particles move slower

The accelerator will give particles of the same charge the same energy. So I would expect heavy particles to move slower than light ones.

And because they are moving slower they would be less affected by the magnet.

If this analysis is correct then it should be described, and the Mass Selection section is plain wrong because it does not take this into account, and the deflections would be greater than it predicts. If my analysis is wrong then it is a pretty obvious conclusion and deserves mention. Tuntable (talk) 00:59, 11 February 2020 (UTC)

Tuntable, you are correct that velocities due to acceleration by a static electrical potential are also a function of the mass and will affect any downstream physics. This is the basis of TOF-MS. This effect is important in nearly all MS. However, it is indeed accounted for in a full physical description of any specific mass spectrometry configuration. The fundamental principles of different mass analyzers or other components are separable and they not necessarily intertwined in only one way. For example, ions exiting an RF pseudopotential well will not generally follow the 1/2 mv^2 relationship you want to insert into the fundamentals of a magnetic sector and can approach equal velocity across a wide range of masses. There is nothing wrong with the current description. It is simple yet fundamental. There probably is room for a separate section on the practicalities of different configurations and the interplay between elements as well as other non-idealized realities such as space charging and ion dispersion. --Nick Y. (talk) 22:58, 17 February 2020 (UTC)

Respired Gas Monitor section

It might not be germane to Wikipedia's goals but it is noted that this section speaks in good detail about what the situation was, but not the reason for sudden discontinuation in hospitals around 2000 or what the benefits of the replacement method(s) were. — Preceding unsigned comment added by 50.34.107.192 (talk) 18:08, 28 December 2020 (UTC)

Ion Mobility section

It is noted that this section only covers minimum amount of information on how ion mobility can be coupled with mass spectrometry instruments. The value of ion mobility sometimes acts as an important ionization technique for mass spectrometry is not critically evaluated. --Bruce2413 (talk) 07:30, 4 February 2022 (UTC)

mass/charge compared to mass

This statement appears in the section on hard ionization: "Resultant ions tend to have m/z lower than the molecular mass." Perhaps I'm missing something, but why is mass being compared to the ratio of mass to charge? 68.162.214.137 (talk) 00:15, 5 July 2022 (UTC)

I changed it to 'molecular ion'. Hopefully that is more clear now. –CWenger (^ • @) 15:21, 9 July 2022 (UTC)

TOF description is confusing

Understanding the section on TOF requires prior knowledge of TOF. First, this sentence is difficult to parse:

"The initial velocity is often not dependent on the mass of the ion TOF-MS, and will turn into a difference in the final velocity."

This sentence is even more confusing:

"...since the average starting velocity of ions relative to the other analyzed ions is generally centered at zero."

This seems to be referring to differences in velocity. 68.162.214.137 (talk) 13:35, 9 July 2022 (UTC)

It was pretty verbose. I tried to clean it up so hopefully it's a little clearer now. –CWenger (^ • @) 15:14, 9 July 2022 (UTC)

History section is a mess

I'm making this request because I am a paid mass spectroscopist and therefore have a conflict of interest. I am also editing from an IP and therefore expect that were I to make the change myself it would be reverted.

• Specific text to be added or removed: In the history section, please change the legend of the picture currently identified as "Replica of J.J. Thomson's third mass spectrometer" to "Replica of F.W. Aston's third mass spectrometer"
• Reason for the change: That's what it is. It was made by Aston, not by Thomson; Thomson made the parabola spectrograph, which preceded Aston's instruments, and was different.
• References supporting change: If you open the picture in Commons, you'll see that the uploader identified it as Aston's, not Thomson's. The same image is used in History_of_mass_spectrometry and Francis_William_Aston where it is identified as Aston's, not Thomson's. There is a similar picture in [1] if you need something independent of WP. The item itself is in the Cavendish labs museum, who also identify it as Aston's, with a clear image here: [2]

149.155.219.44 (talk) 16:47, 17 August 2022 (UTC)

 Done Ptrnext (talk) 18:00, 17 August 2022 (UTC)